Merge pull request #3973 from minrk/26nosuper

logging.Formatter is not new-style in 2.6

add workaround and regression test

IPython/config/application.py

@@ -115,8 +115,10 b' class LevelFormatter(logging.Formatter):'
             record.highlevel = self.highlevel_format % record.__dict__
         else:
             record.highlevel = ""
-        
-        return super(LevelFormatter, self).format(record)
+        if sys.version_info[:2] > (2,6):
+            return super(LevelFormatter, self).format(record)
+        else:
+            return logging.Formatter.format(self, record)
             
 
 class Application(SingletonConfigurable):

IPython/config/tests/test_application.py

@@ -18,8 +18,11 b' Authors:'
 #-----------------------------------------------------------------------------
 
 import logging
+from io import StringIO
 from unittest import TestCase
 
+import nose.tools as nt
+
 from IPython.config.configurable import Configurable
 from IPython.config.loader import Config
 
@@ -80,6 +83,16 b' class MyApp(Application):'
 
 class TestApplication(TestCase):
 
+    def test_log(self):
+        stream = StringIO()
+        app = MyApp(log_level=logging.INFO)
+        handler = logging.StreamHandler(stream)
+        # trigger reconstruction of the log formatter
+        app.log.handlers = [handler]
+        app.log_format = "%(message)s"
+        app.log.info("hello")
+        nt.assert_in("hello", stream.getvalue())
+
     def test_basic(self):
         app = MyApp()
         self.assertEqual(app.name, u'myapp')